Development of novel biomedical sterilization technology is proposed. The method utilizes supercritical C02, which allows for the sterilization of materials that are incompatible with current methods. This technology can be applied to a variety of biomedical materials, including thermally and hydrolytically sensitive polymers, as well as biopolymers. The method will find application in sterilizing numerous biomedical materials. Initial results showed complete inactivation of a variety of vegetative microorganisms, with short exposure times (0.6-4.0 h) and low temperatures (25-60 C). Attached macromolecules (proteins, nucleic acids, biodegradable drug delivery matrices) that might be damaged by existing sterilization methods have been shown to be compatible with C02. Specific aims include (1) to achieve the inactivation of bacterial spores by developing certain process modifications to improve the overall methodology; (2) to conduct a screening study to evaluate the influence of individual additives on the efficiency of sterilization; (3) to develop combinations of process modifications and additives, based on findings in Aims 1 and 2, that would inactivate high concentrations of bacterial spores. The long-term objective of this project is to develop a commercially viable sterilization method that would be compatible with emerging biomaterials and biomimetic structures and would eventually replace ethylene oxide as a sterilization method. In particular, sterilization of the new synthetic extracellular matrix, a.k.a. synthetic skin, not compatible with any other sterilization method, will be investigated in collaboration with the original inventor of the synthetic skin at the University of Utah. The new C02-based sterilization technology produces no environmentally hazardous byproducts, and should be readily transferred to biomedical industry. The commercial reactors would use C02 on closed-system basis (similar to many existing C02-based extraction systems) where used C02 would be purified and reused again (complete recycling system).